If the name Skylar Grey rings a bell, it is probably either due to her featured singing and/or songwriting on tracks like Dr. Dre’s “I Need a Doctor,” Diddy-Dirty Money’s “Coming Home,” and “Love the Way You Lie” by Rihanna and Eminem. If the music gods smile favorably upon her, Grey will soon be known as a solo artist in her own right, thanks to the gifts for melody and turning a phrase displayed on this captivating debut under her current nom de pop. (Born Holly Hafermann, Grey cut an album in the mid ’00s as “Holly Brook.”) Befitting someone who has worked with artists as varied as Dre, Duncan Sheik, and Linkin Park offshoot Fort Minor, “Don’t Look Down’’ suits varied moods. One minute she’s getting silly with Eminem, who co-executive produced the set with “Lie” co-writer Alex Da Kid, on the throwaway innuendo happy jam “C’mon Let Me Ride,” the next she’s crooning a weary, Fiona Apple-style ballad “Wear Me Out” only to veer into woozy trip-hop territory with “Glow in the Dark.” (Out Tuesday)